SolidWorks block files are created when a custom part is placed in a 3D CAD file. It is a collection of data that can be imported into other CAD software and used as a template.
SolidWorks block files contain the geometry, manufacturing, and design intent information needed to create a new solid model from the existing one. These include information about the part's dimensions, tolerances, hole dimensions, material properties, and layers.
you can also add colors to your model by adding colors to your block file. In addition to these colors being applied throughout your design by using color swatches or color filters in your drawing cells or sketch table cells.